This invention relates to a novel method for preventing or reducing post-ischaemic injury of the heart, in particular myocardial infarction or for improving the functional recovery of the heart following myocardial ischaemia.
Cardiovascular disease is a leading cause of mortality in adult diabetics of both Type 1 and Type 2 etiologies. The underlying presence of cardiovascular disease in diabetes means not only that the likely incidence of myocardial infarction is higher in the diabetic population but that its occurrence carries a substantially greater risk of mortality for diabetics than non-diabetics. European Patent Application, Publication Number 0,306,228 relates to certain thiazolidinedione derivatives disclosed as having antihyperglycaemic and anti-hyperlipidaemic activity. One particular thiazolidinedione disclosed in EP 0306228 is 5-[4-[2-(N-methyl-N-(2-pyridyl)amino)ethoxy]benzyl]thiazolidine-2,4-dione (hereinafter xe2x80x98Compound (I)xe2x80x99). WO94/05659 discloses certain salts of Compound (I) including the maleate salt at example 1 thereof.
Compound (I) is an example of a class of anti-hyperglycaemic agents known as xe2x80x98insulin sensitisersxe2x80x99. In particular Compound (I) is a thiazolidinedione insulin sensitiser. Thiazolidinedione insulin sensitisers include compounds comprising a 2,4-thiazolidinedione moiety.
European Patent Applications, Publication Numbers: 0008203, 0139421, 0032128, 0428312, 0489663, 0155845, 0257781, 0208420, 0177353, 0193256, 0319189, 0332331, 0332332, 0528734, 0508740; International Patent Application, Publication Numbers 92118501, 93/02079, 93/22445 and U.S. Pat. Nos. 4,687,777, 5,104,888 and 5,478,852, also disclose certain thiazolidinedione insulin sensitisers.
Another series of compounds generally recognised as having insulin sensitiser activity are those typified by the compounds disclosed in International Patent Applications, Publication Numbers WO93/21166 and WO94/01420. These compounds are herein referred to as xe2x80x98acyclic insulin sensitisersxe2x80x99. Other examples of acyclic insulin sensitisers are those disclosed in U.S. Pat. No. 5,232,945 and International Patent Applications, Publication Numbers WO92/03425 and WO91/19702.
Examples of other insulin sensitisers are those disclosed in European Patent Application, Publication Number 0533933, Japanese Patent Application Publication Number 05271204, and U.S. Pat. No. 5264451.
The above mentioned publications are incorporated herein by reference.
It is suggested by Shimabukuro et al (Diabetes 44[Suppl 1]:797 (Abstract) 1995) that long term treatment with the thiazolidinedione, troglitazone, preserves cardiac function of the diabetic heart. Also, Eckel et al (Diabetes, 46 [Suppl 1]: 575 (Abstract) 1997) have suggested that chronic exposure to troglitazone may exert a cardioprotective effect by increasing glucose supply to the myocytes of the diabetic heart.
It is now surprisingly indicated that the acute administration of Compound (I) exerts a cardioprotective effect on the diabetic heart and is therefore, effective at preventing or reducing post-ischaemic injury, such as myocardial infarction. The acute administration of Compound (I) is also indicated to improve the functional recovery of the diabetic heart following myocardial ischaemia.
In addition, and perhaps more surprisingly, it is indicated that administration, especially acute administration, of Compound (I) exerts a particularly effective cardioprotective effect on the non-diabetic heart.
Accordingly, the present invention provides a method for reducing post-ischaemic injury of the heart, in particular myocardial infarction, which method comprises administration, especially acute administration, of an effective, non-toxic amount of a glucose uptake enhancer to a human or non-human mammal in need thereof.
The invention also provides a method for improving the functional recovery of the heart following myocardial ischaemia which method comprises administration, especially acute administration, of an effective, non-toxic amount of a glucose uptake enhancer to a human or non-human mammal in need thereof.
In one particular aspect the invention provides a glucose uptake enhancer, such as Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, for use in reducing post-ischaemic injury of the heart, in particular myocardial infarction or for use in improving the functional recovery of the heart following myocardial ischaemia.
Certain of the human or non-human mammals may be suffering from diabetes mellitus or a related disorder. Particularly, the diabetes mellitus is Type 1 diabetes mellitus. Particularly, the diabetes mellitus is Type 2 diabetes mellitus.
A suitable glucose uptake enhancer is an insulin sensitiser.
A suitable glucose uptake enhancer is a thiazolidinedione.
Suitable thiazolidinediones are those disclosed in the above mentioned publications.
A preferred thiazolidinedione is Compound (I), or the tautomeric form thereof, or a pharmaceutically acceptable derivative thereof.
Other suitable thiazolidinediones include (+)-5-[[4-[(3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)methoxy]phenyl]methyl]-2,4-thiazolidinedione (or troglitazone), 5-[4-[(1-methylcyclohexyl)methoxy]benzyl]thiazolidine-2,4-dione (or ciglitazone), 5-[4-[2-(5-ethylpyridin-2-yl)ethoxy]benzyl]thiazolidine-2,4-dione (or pioglitazone) or 5-[(2-benzyl-2,3-dihydrobenzopyran)-5-ylmethyl)thiazolidine-2,4-dione (or englitazone); or a pharmaceutically acceptable derivative thereof.
A suitable pharmaceutically acceptable derivative is a pharmaceutically acceptable salt or a pharmaceutically acceptable solvate, including a pharmaceutically acceptable solvate of a pharmaceutically acceptable salt.
Suitable pharmaceutically acceptable derivatives, including pharmaceutically acceptable salts and pharmaceutically acceptable solvates, of the glucose uptake enhancer, for example the thiazolidinediones, are as described in the above mentioned publications and standard reference texts such as the British and US Pharmacopoeias, Remington""s Pharmaceutical Sciences (Mack Publishing Co.), Martindale The Extra Pharmacopoeia (London, The Pharmaceutical Press).
Suitable pharmaceutically acceptable salts of Compound (I) include those described in EP 0306228 and WO94/05659. A preferred pharmaceutically acceptable salt is a maleate.
Suitable pharmaceutically acceptable solvated forms of Compound (I) include those described in EP 0306228 and WO94/05659, in particular hydrates.
Certain of the glucose uptake enhancers, such as the thiazolidinediones, for example Compound (I), may exist in one of several tautomeric forms, all of which are encompassed by the method of the invention, either as individual tautomeric forms or as mixtures thereof.
Certain of the glucose uptake enhancers, such as the thiazolidinediones, for example Compound (I), may also contain chiral carbon atoms, and hence can exist in several stereoisomeric forms, all of which are encompassed by the method of the invention whether as individual isomers or as mixtures of isomers.
The glucose uptake enhancers, such as the thiazolidinediones, including the pharmaceutically acceptable derivatives thereof, are prepared using conventional methods; for example the thiazolidinediones are conveniently prepared according to the methods disclosed in the above mentioned publications: Thus Compound (I), or the tautomeric form thereof, or a pharmaceutically acceptable derivative thereof, such as a salt thereof or a pharmaceutically acceptable solvate thereof, may be prepared using the processes described in EP 0306228 and WO94/05659.
The above mentioned stereoisomeric forms, such as those of the thiazolidinediones, may be prepared and separated as required, according to known methods such as those disclosed in the above mentioned publications.
The above-mentioned feature of the acute administration of glucose uptake enhancer, especially of the thiazolidinediones such as Compound (I), is considered to comprise in its own right a further part of the present invention. Accordingly, the invention further provides a glucose uptake enhancer, such as a thiazolidinedione for example Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, for use as an acutely administerable therapeutic substance.
The present invention also provides a glucose uptake enhancer, such as a thiazolidinedione for example Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, for use as an acutely administrable cardioprotective agent, especially for preventing or reducing post-ischaemic injury of the heart, in particular myocardial infarction,
The present invention also provides a glucose uptake enhancer, such as a thiazolidinedione for example Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, for acute administration for improving the functional recovery of the heart following myocardial ischaemia.
In all of the above-mentioned treatments, the glucose uptake enhancer such as Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, may be administered per se or, preferably, as a pharmaceutical composition also comprising a pharmaceutically acceptable carrier.
Accordingly, the present invention also provides a pharmaceutical composition comprising a glucose uptake enhancer, such as Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, and a pharmaceutically acceptable carrier wherein such composition is adapted for acute administration.
More particularly, the present invention provides a pharmaceutical composition for use as an acutely administerable cardioprotective agent, especially for preventing or reducing post-ischaemic injury of the heart, in particular myocardial infarction, which composition comprises a glucose uptake enhancer, such as Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, and a pharmaceutically acceptable carrier.
The invention further provides a pharmaceutical composition for acute administration for improving the functional recovery of the heart following myocardial ischaemia, which composition comprises a glucose uptake enhancer, such as Compound (I) or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof, and a pharmaceutically acceptable carrier.
It is also envisaged that the acute cardioprotective effect of a glucose uptake enhancer would be useful for enhancing post-surgical recovery. Accordingly, the invention further provides a method for enhancing recovery after surgery, especially major surgery, for example cardiac surgery, which method comprises administration, generally acute administration, of an effective, non-toxic amount of a glucose uptake enhancer such as Compound (I), or a tautomeric form thereof or a pharmaceutically acceptable derivative thereof. Said administration of the glucose uptake enhancer may be before or after surgery. Particular patient groups include the elderly such as post-60 year age groups.
As used herein the term xe2x80x9cpharmaceutically acceptablexe2x80x9d embraces compounds, compositions and ingredients for both human and veterinary use: for example the term xe2x80x98pharmaceutically acceptable saltxe2x80x99 embraces a veterinarily acceptable salt.
As used herein xe2x80x9cpost-ischaemic injury of the heartxe2x80x9d includes myocardial infarction and certain arrhythmias, especially due to myocardial infarction.
As used herein xe2x80x9cimproving the functional recovery of the heartxe2x80x9d includes improving or restoring cardiac output and/or enhancing the recovery, especially the rate of recovery, of cardiac output.
As used herein xe2x80x9cacute administrationxe2x80x9d or phrases or terms used to convey an equivalent meaning to acute administration refer to a single administration of the medicament or the short term use. Short term use of a thiazolidinedione insulin sensitiser means a period of time less than that associated with an antihyperglycaemic effect. A suitable short term use period is 3-4 weeks.
As used herein xe2x80x9cglucose uptake enhancerxe2x80x9d means an agent which increases basal (insulin independent) or insulin-stimulated uptake of glucose into a cell.
In the method of the invention, the active medicaments are preferably administered in pharmaceutical composition form.
Usually the compositions are adapted for oral administration. However, they may be adapted for other modes of administration, for example parenteral administration, sublingual or transdermal administration.
The compositions may be in the form of tablets, capsules, powders, granules, lozenges, suppositories, reconstitutable powders, or liquid preparations, such as oral or sterile parenteral solutions or suspensions.
In order to obtain consistency of administration it is preferred that a composition of the invention is in the form of a unit dose.
Unit dose presentation forms for oral administration may be tablets and capsules and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinylpyrrolidone; fillers, for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricants, for example magnesium stearate; disintegrants, for example starch, polyvinylpyrrolidone, sodium starch glycollate or microcrystalline cellulose; or pharmaceutically acceptable wetting agents such as sodium lauryl sulphate.
The compositions are preferably in a unit dosage form in an amount appropriate for the relevant daily dosage.
Suitable dosage regimens, including details of unit dosages, for the thiazolidinediones include those described in the above mentioned publications or in reference texts such as the British and US Pharmacopoeias, Remington""s Pharmaceutical Sciences (Mack Publishing Co.), Martindale The Extra Pharmacopoeia (London, The Pharmaceutical Press).
The compositions are preferably in a unit dosage form in an amount appropriate for the relevant daily dosages. For example, for compound (I), unit doses suitably contain up to 12 mg of Compound (I).
In the acute treatment of the invention, the glucose uptake enhancer, such as Compound (I), or the tautomeric form thereof, or a pharmaceutically acceptable derivative thereof, is generally administered as a single dose. However, if required, additional doses may be administered to provide suitable short-term, non-chronic treatments, for example to prevent or reduce post-ischaemic injury, such as myocardial infarction, due to a subsequent ischaemic event and/or to prevent or reduce the severity of such an event and/or its re-occurrence.
In the above mentioned acute administration of glucose uptake enhancers, for example thiazolidinediones, dosages are envisaged to include higher doses than those associated with an anti-hyperglycaemic effect.
In a further aspect the treatment comprises the sequential administration or the co-administration of a thrombolytic agent, such as streptokinase, with the glucose uptake enhancer, such as Compound (I) or the tautomeric form thereof, or a pharmaceutically acceptable derivative thereof.
Accordingly, the invention also comprises a pharmaceutical composition comprising a glucose uptake enhancer, such as Compound (I) or the tautomeric form thereof, or a pharmaceutically acceptable derivative thereof, and a thrombolytic agent, such as streptokinase, and a pharmaceutically acceptable carrier.
The particular thrombolytic agent and its required dosage include those described in reference texts such as the British and US Pharmacopoeias, Remington""s Pharmaceutical Sciences (Mack Publishing Co.), Martindale The Extra Pharmacopoeia (London, The Pharmaceutical Press). The solid oral compositions may be prepared by conventional methods of blending, filling or tabletting. Repeated blending operations may be used to distribute the active agent throughout those compositions employing large quantities of fillers. Such operations are of course conventional in the art. The tablets may be coated according to methods well known in normal pharmaceutical practice, in particular with an enteric coating.
Oral liquid preparations may be in the form of, for example, emulsions, syrups, or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example sorbitol, syrup, methyl cellulose, gelatin, hydroxyethylcellulose, carboxymethylcellulose, aluminium stearate gel, hydrogenated edible fats; emulsifying agents, for example lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters such as esters of glycerine, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl p-hydroxybenzoate or sorbic acid; and if desired conventional flavouring or colouring agents.
For parenteral administration, fluid unit dosage forms are prepared utilizing the compound and a sterile vehicle, and, depending on the concentration used, can be either suspended or dissolved in the vehicle. In preparing solutions the compound can be dissolved in water for injection and filter sterilized before filling into a suitable vial or ampoule and sealing. Advantageously, adjuvants such as a local anaesthetic, a preservative and buffering agent can be dissolved in the vehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum. Parenteral suspensions are prepared in substantially the same manner, except that the active compound may be suspended in the vehicle instead of being dissolved, and sterilization cannot be accomplished by filtration. The compound can be sterilized by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the compound.
Compositions may contain from 0.1% to 99% by weight, preferably from 10-60% by weight, of the active material, depending upon the method of administration.
Compositions may, if desired, be in the form of a pack accompanied by written or printed instructions for use.
Finally, the cardioprotective effects, especially the acute cardioprotective effects, of a glucose uptake enhancer, such as Compound (I) or the tautomeric form thereof, or a pharmaceutically acceptable derivative thereof, are also considered to provide potential for use as a cardioplegic agent. Accordingly, the present invention also provides a glucose uptake enhancer, such as Compound (I) or the tautomeric form thereof, or a pharmaceutically acceptable derivative thereof for use as a cardioplegic agent, especially in cardioplegic solutions, to preserve cardiac function during surgery.
Particular uses of a cardioplegic agent include use in cardiac by-pass surgery. Particular uses of a cardioplegic agent include use in cardiac transplant surgery for maintaining cardiac viability.
The amount of active agent required for cardioplegic use will be provided by standard tests methods such as those described herein, for example cardioplegic solutions of Compound (I) are envisaged to contain between 0.0 1 xcexcM and 10 xcexcM of Compound (I).
In a further aspect, the invention also provides a pharmaceutical composition, adapted for use as a cardioplegic agent, which comprises a glucose uptake enhancer, such as Compound (I) or a tautomeric form thereof, or a pharmaceutically acceptable derivative thereof and a pharmaceutically acceptable carrier.
The compositions are prepared and formulated according to conventional methods, such as those disclosed in standard reference texts, for example the British and US Pharmacopoeias, Remington""s Pharmaceutical Sciences (Mack Publishing Co.), Martindale The Extra Pharmacopoeia (London, The Pharmaceutical Press and Harry""s Cosmeticology (Leonard Hill Books) or the above mentioned publications.
The cardioprotective effects of the invention may be identified by using test methods such as those provided hereinafter or those known in the art such as those disclosed in Khandoudi N, Bernard M, Cozzone P, Feuvray D (Intracellular pH and role of Na+/H+ exchange during ischaemia and reperfusion of normal and diabetic rat hearts. Cardiovasc Res 24: 873-878, 1990) or in Khandoudi N, Laville M P, Bril A (Protective effect of the Sodium/Hydrogen exchange inhibitors during global low flow-ischemia. J Cardiovasc Pharmacol 28: 540-546, 1996).
No adverse toxicological effects have been established for the compositions or methods of the invention in the above mentioned dosage ranges.
In the Tables and Figures shown below:
Table 1: shows baseline ventricular function of isolated working hearts from male Wistar rats: with vehicle or Compound (I) added to the perfusate pre-ischaemia; and
Table 2: shows baseline ventricular function of isolated working hearts from STZ-diabetic rats: with vehicle or Compound (I) added to the perfusate pre-iscaemia;